"BlackBerry 10 is completely different from previous BlackBerry operating systemsâ€"with good reason. Its core assets come from a company named QNX, which Research In Motion acquired in 2010. Blackberry 10 features include 'live tiles' that dynamically refresh with new information, as well as a revamped keyboard and security upgrades. But what really makes or breaks a phone is the quality (and quantity) of its third-party apps. So what we'll do here is look at the programming API. That will give us a good grip on what app developers can do with the platform."

1. Who is buying BlackBerry?
2. What are the needs of those users?
3. Which of those needs are not served at present?

Now ask yourself: do you have the skill and motivation to address those needs? If the answer is yes, then it is probably worth your development time. If the answer is no, then you'd probably end up developing something that won't sell (i.e. it isn't worth your development time).

Keep in mind, BlackBerry is still a large market and that many developers would love to tap a market that large. That's especially true for specialized applications that BlackBerry users are more likely to need. The only reason why BlackBerry's market looks small is because iOS and Android have a much larger market share. On the other hand, the needs of those markets are more diverse and you have a lot more competition from other developers.

Also keep in mind that the main reason for the decline of BlackBerry is the rise of the smartphone. BlackBerry was always a relatively small segment of the market when you compared it to total mobile phone sales. The difference is that it used to have a larger share of the smartphone market, but that's solely because most people bought basic or feature phones.